( 758 ) 



column K remain between the indications of the auxiliary manometer 



and the open standard manometer. These differences, considerably 



smaller than those in table XVII of Comm. N°. 78", remain within 



(he limits of accuracy fixed for this investigation, and justify us to 



1 



estimate the mean error in the pressure measurements at ± . 



1 3000 



In the following the pressures have been calculated with this new 

 value of the normal volume. 



§ 4. The piezometers and auxiliary up paralus. 



The piezometer used in the tirst series for the observations at a 

 density 70 and the temperatures —104°, —136°, —183°, —195°, was 

 of about the same dimensions as that used for the observations ot 

 Comm. N°. 78. In the subjoined table, just as in the corresponding 

 table II of that communication, the dimensions are given to facilitate 

 a survey of the amount and the influence of the many corrections. 



l ) The values of (3 given here have been determined for the ordinary temperature 

 and those for lower temperatures have been put equal to them. We hope soon to 

 determine (3 also for lower temperatures. 



